Add all the values together: ( text{sum} = x_1 + x_2 + cdots + x_n )
Divide the sum by the number of values: ( text{mean} = dfrac{text{sum}}{n} )
For a data set of (n) values (x_1, x_2, ldots, x_n): ( bar{x} = dfrac{1}{n}sum_{i=1}^{n} x_i )
For a weighted mean (values (x_i) with weights (w_i)): ( bar{x}_w = dfrac{sum_{i=1}^{n} w_i x_i}{sum_{i=1}^{n} w_i} )